Abstract

Details on the generation of (multiple) quasimonoenergetic electron bunches in the self-modulated laser wakefield acceleration (SMLWFA) regime are presented. This type of laser-plasma interaction can result in pronounced longitudinal laser pulse fragmentation, dependent on plasma density and laser intensity. It is shown by experiments and particle-in-cell simulations that these laser pulse fragments can be powerful enough to trigger nonlinear plasma wave breaking, injection, and acceleration of electrons to quasimonoenergetic energies. With high plasma densities, self-modulation is promoted, and the advantages of SMLWFA such as especially high accelerating fields and short electron bunches can be harvested. In addition, more than one quasimonoenergetic electron bunch can be created, with a temporal spacing between each bunch of only few tens of femtoseconds, again governed by plasma density.

Received 23 January 2009Accepted 06 March 2009Published online 14 April 2009

Acknowledgments:

This work was supported by DFG-Projects Transregio TR18 and Graduiertenkolleg GRK1203. We thank the staff at the Institut für Optik und Quantenelektronik at the Friedrich-Schiller-Universität Jena, Germany, for reliable laser operation and excellent support during the experimental campaigns.